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arXiv · 2410.14583

Hidden Kondo lattice physics in single-orbital Hubbard models

Philipp Werner·Sayed Ali Akbar Ghorashi
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Abstract

Single-orbital Hubbard models exhibit remarkably nontrivial correlation phenomena, even on nonfrustrated bipartite lattices. Some of these, like non-Fermi-liquid metal states, or the coexistence of heavy and light quasi-particles, are reminiscent of the properties of more complex multi-orbital or Kondo-lattice systems. Here, we use basis transformations to map single-orbital models to effective multi-orbital descriptions and clarify how a ferromagnetic Kondo-lattice-like behavior emerges in prototypical models with flat bands or van Hove singularities in the density of states: the Hubbard model on the diamond chain, square-lattice, Lieb lattice and honeycomb lattice. In particular, this mapping explains the non-Fermi-liquid states and pseudo-gaps found in the correlated metal regime.

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Philipp Werner, Sayed Ali Akbar Ghorashi. 2024-10-18. Hidden Kondo lattice physics in single-orbital Hubbard models. https://doi.org/10.1103/physrevb.111.045138

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